PIPE SYSTEMS INDUSTRY

FLUORINATION

Surface finishing

The demands on the characteristics of commodities' surface structure become higher and higher. Beside an attractive and touch-appealing design with the help of lacquering, environmental aspects are also top priority. Polymers – which are ideal with respect to processing and creation possibilities – often encounter their limits due to poor adhesion and negative wetting properties. These deficits can be eliminated economically and permanently with the help of fluorination. With only one working step, without mechanical load, the surface tension is altered. Hydrogen atoms of the molecular chains are substituted with fluorine atoms and one obtains new characteristics:

OPERATING PRINCIPLE OF THE FLUORINATION

Before the fluorination

Plastics show excellent qualities as easy processing, low weight and high chemical resistance. Fluorination offers an effective opportunity to expand the range of application possibilities.

Fluorination

The strong responsiveness of the fluorine gas causes the substitution of hydrogen atoms by fluorine atoms on the surface of the component. The altered surface layer shows a high binding energy and is thus very resistant.

After the fluorination

After the fluorination, the surface layer is permanently modified, has excellent adhesive characteristics, shows a strikingly lower permeation towards other substances and has a better floating and reaming performance.

EXAMPLES OF USE

Pre-treatment of plastic parts for the subsequent leather lining

Liquid container with decreased
permeation (permeability of gases)

Pre-treatment of plastic parts
for the subsequent, long-lasting adhesion of other components

TECHNICAL DETAILS

Excellent adhesion

With the fluorination, the wettability of the plastics increases. The wettability is an important requirement for a sufficient adhesion of lacquers and adhesives. The higher the surface tension, and so the wettability of the surface to be finished, the better these surfaces can be lacquered. This relatively high penetration of the fluorine – which can be found in the range of ….. - is additionally causing the stable and long-lasting effect of the fluorination. Therefore, the pretreatment is maintained even with moving molecules, caused for example by temperature change. Compared to the common pretreatment methods, this thick and modified surface of multiple molecule layers shows significant advantages especially with all objects which are subject to increased exposure before the treatment.

The permeation of liquids (here toluene) and gases with polymer components can often be reduced by orders of magnitude with fluorination.

reduced permeation

With the possibility to lower the gas and liquid permeability of plastic components with the help of fluorination, economic and ecological aspects can be combined. On the one hand, a loss of volume and change of properties of the products can be avoided, and an environmental impact by fumes and odors can be reduced. On the other hand, cost-efficient, light and economically- as well as resource-friendly packing can be used.

non-fluorinated

Fluorinated

PE

32

70

PP

29

70

POM

40

72

PET

32

72

PBT

30

72

PC

32

70

EPDM

40

58

water

70

-

safety due to increased surface energy

The improved surface properties by means of fluorination, give more security for the processing of the components to be redefined. For the lacquering no primer is needed since the fluorinated surface offers a perfect adhesion basis. The achievable improvement of the surface energy depends primarily on the duration of the fluorination, the temperature and the amount of fluorine gas used. The adjustment of these parameters is a decisive aspect of Maincor's competence. Consulting service is for Maincor a question of qualification since behind every product sold lies a huge responsibility.

ADVANTAGES OF THE PROCESS

The offline fluorination is a testified method of plastic surface treatment. In comparison to other treatments as flame impingement, Corona and plasma, the fluorination offers significant advantages:

The fluorine penetrates deep into the material and so causes a stable surface layer which is not even altered by molecule movements. …. Due to the fissility of the fluorine's gaseous form, fluorination is not only on the outside but also on the inside of the hollow body possible. The surface is not subject to mechanical or thermal load. The basic characteristics of the material remain the same, merely the layers near the surface are modified. From an environmental point of view, this treatment can be considered as absolutely harmless.

RESEARCH AND DEVELOPMENT

In order to determine the various possibilities of the fluorination, MAINCOR decided to investigate fundamentally the theoretical and application-specific characteristics of fluorination in cooperation with partner universities. This includes especially the properties of the polymer surfaces depending on the fluorination parameters as well as the aging time, which are supposed to be correlated with the application-specific parameters of the adhesion.

The effect of fluorination for new party is tested in long term tests. The result of these studies give customer the safety of acquiring a reliable service for his products.